Athletic shoe for racing and training

ABSTRACT

An athletic shoe particularly adapted for use in racing and training, having a tilted cleat configuration on the sole for contacting the running surface in a manner to provide good traction while effectively cushioning the foot and leg of the wearer when the foot strikes the ground.

BACKGROUND OF THE INVENTION

With the advent of artificial surfaces for competitive running whichsurfaces usually are harder than previously used natural surfaces, ithas been found necessary to cushion the runner's foot as much aspossible to lessen the shock resulting as the foot is set down. Oneexample of such cushioning is shown in the U.S. Pat. No. 4,085,527,entitled: ATHLETIC SHOE and issud on Apr. 25, 1978, with the sameinventor as this application. Such cushioning is provided in the shoe ofthat patent by resilient cleats positioned on the bottom of the sole andextending vertically downward toward the running surface. These cleatsprovide both traction and cushioning as the foot contacts the runningsurface.

It is the purpose of this invention to provide an improved cleat designfor athletic shoes which enhances both the traction and the cushioningeffect rendered to the runner.

SUMMARY OF THE INVENTION

An athletic shoe having an upper portion for receiving the foot, with asole attached presenting a bottom planar surface for contacting therunning surface. Fixed to this planar surface are a plurality ofresilient cleats extending generally downward to contact the runningsurface. These cleats are fixed at angles other than 90° to the planarsurface so as to facilitate compression and bending thereof forcushioning the foot while increasing the ability of the cleats towithstand the forces exerted between the shoe and the running surfaceduring periods of acceleration, stopping and turning.

DESCRIPTION OF THE INVENTION

FIG. 1 is a side plan view of an athletic shoe incorporating oneembodiment of the subject invention;

FIG. 2 is a bottom view of the shoe of FIG. 1;

FIG. 3 is an enlarged cross-sectional view of a portion of the sole andcleats of the shoe in FIG. 2 taken along the line 3--3 thereof; and

FIG. 4 is the view of FIG. 3 showing the flexing of the cleats as theshoe contacts the running surface.

DESCRIPTION OF THE INVENTION

As shown primarily in FIGS. 1 and 2, the invention is embodied in anathletic shoe 15 including an upper portion 16 formed to enclose thefoot of the wearer. The shoe upper portion is of a normal type usuallybeing formed of leather or a synthetic material, or a combinationthereof, and being laced by shoestrings 17A passed through the eyelets17. The shoe upper portion includes a heel portion 18, a toe portion 19,and a center or shank portion 20 which supports the arch and ball areasof the foot. The heel portion also includes a heel counter 23 formed toenclose and support the heel. The upper portion supports a sole 21 whichforms the wear surface for contacting the running surface. The sole isfixed to the upper portion in a suitable manner, such as by gluingand/or sewing.

Fixed to the bottom planar surface 24 of the sole 21 are a plurality ofcleats 25 positioned in a manner to extend generally downward to contactthe running surface when the shoe is worn. These cleats preferably aremolded integrally with the sole or a portion of the sole and are made ofrubber or a similar resilient material to provide both traction andcushioning for the foot. Cushioning is also partially provided by amidsole 26 sandwiched between the cleats and the upper portion, whichmidsole is made of a resilient material such as rubber or the like. Inthe normal functioning of such shoes, this midsole tends to give orcompress as pressure is exerted thereon as the cleats contact theground. With the cleats being positioned primarily to extend normal tothe bottom planar surface 24 of the sole they also tend to compress asthe foot is set on the running surface for cushioning of the foot.

However, the providing of cushioning for the foot can decrease thestability of the shoe with the running surface. With the cleatsextending normal to the sole bottom, they are placed both in directcompression and in shear during a turning or accelerating maneuver bythe wearer. Thus the cleats tend to bend if they are sufficiently longto provide a large amount of cushioning whereas the shorter cleatsprovide less cushioning. The direction of such bending is unpredictableand depends on the direction of the shear forces exerted between thefoot and the ground. However such a bending or rolling action by thecleats does tend to lessen the stability of the foot and also may tendto lessen the traction with the running surface since the flat bottomsurface of the cleat may roll over sidewise under excessive bending.

Some attempts have been made to use shorter cleats and compensate forany loss in cushioning by increasing the thickness of the midsole.However the midsole, in extending across the total bottom surface of theshoe, represents a substantial portion of the shoe weight. Therefore anyincrease in thickness of this midsole can make the shoe considerablyheavier, a factor of special significance in athletic racing shoes. Themidsole must be of sufficient thickness to assure that the compressionof it does not extend through sufficiently to bulge an exert a pressureon specific areas of the wearer's foot.

In accordance with one feature of the invention, the cleats are fixed tothe bottom planar surface 24 of the midsole so as to extend downward atan angle other than normal to the midsole surface. As shown primarily inFIGS. 2 and 3, the cleats 27 and 28 extend with the respective axes 29and 30 at an angle other than normal to the plane of the midsolesurface. In the invention, the angle between each axis and this solesurface can range between 15 degrees and 89 degrees. The purpose forpositioning these cleats at this attitude is demonstrated primarily inFIG. 4 showing these same cleats as they would appear under the force ofbeing pressed against the running surface 31 while shear forces arebeing encountered as can be caused by turning, etc. As can be seen, thecleats now have assumed a skewed attitude in which they tend to bend ordistort sideways in the direction originally positioned. At the sametime the midsole in the area 26A and 26B tend to distort to allowfurther cushioning action between the wearing surface and the wearer'sfoot.

Thus it can be seen that by positioning these cleats at an angle, theresilient action theeof is increased in a manner to facilitate thecompression of each cleat and its interaction with the midsole. Sincethe cleats must be made of a sufficiently hard material to wearsatisfactorily, the harder material also tends to compress less. Thus bypositioning the cleats at an angle other than normal to the sole bottomplanar surface, bending and compression of the cleat is increased toenhance the cushioning effect of the sole as well as the durability.

In accordance with another feature of the invention the cleats aretilted in different directions throughout the sole portion of the shoein positions to effectively counteract the particular forces generallyexerted on the cleats in that area of the shoe. For instance under theheel portion 18 of the shoe, the cleats preferably are positioned toextend at angles extending toward the heel and toe portions. Such isaccomplished because acceleration and deceleration actions by the wearertend to exert forces forward and backward on the shoe in the generaldirection parallel to a line extending from toe to heel or heel to toethereof. Thus the cleats tilt parallel to that direction or line andresist distortion sufficiently because of being placed in compressionbetween the sole and the running surface to resist the shear forces andthereby enhance traction with the running surface while increasing thedurability of the sole.

In FIG. 4 a force is being exerted on the shoe in the direction of thearrow 30. Such a force can result primarily during acceleration when theheel is being set down to stop. During this period, the cleats 27 inbeing tilted towards the direction of skid for the shoe, are placed indirect compression to withstand the side forces on the sole.Additionally the lower surfaces 27A tend to remain in parallel contactwith the running surface 31. However if the shoe is pressed straightdownward as in walking or running at a steady pace, the cleats 27 and 28will flex and compress to cushion the contact with the surface in themanner previously described.

Similarly, in the forward portions and toe portions of the soles, thecleats are angled or tilted also towards the side of the shoe or in adirection normal to a line joining the toe and heel areas of the shoe.This angular positioning is achieved to counteract side shear forcesresulting as the wearer runs around turns which action causes sidewiseforces between the shoe and the running surface. In both the toe andheel areas of the sole, the cleats are approximately evenly divided intilting in opposite directions in the embodiment shown. Thus it can beseen that by the particular angular positioning of these cleats, agreater cushioning effect can be accomplished while enhancing theresisting forces between the shoe and the running surface exerted duringparticular momentary actions of the wearer in running.

The invention claimed:
 1. An athletic shoe for running on a runningsurface comprising in combination:a shoe upper portion having heel,shank and toe areas and forming a cavity for receiving the foot; a soleattached to said shoe upper portion for supporting the foot on a runningsurface, said sole comprising: a cushioning pad of resilient materialfixed to the upper portion and forming a bottom planar surface forcontacting the running surface, said pad having side edges extendingfrom the heel to the toe areas of the shoe upper portion; and aplurality of resilient cleats having a truncated cone configurationfixed to the bottom surface of said cushioning pad and projectingtherefrom to contact the running surface, at least a portion of saidcleats tilting at an angle other than normal to said planar surface andtowards the side edges of the pad thereby to facilitate compression ofthe cleats to increase the cushioning and stability of the foot duringrunning.
 2. An athletic shoe comprising in combination:a shoe upperportion having heel, shank and toe areas and forming a cavity forreceiving a foot; a sole attached to said shoe upper portion forsupporting the foot on a running surface, said sole comprising: acushioning pad of resilient material fixed to the upper portion andforming a bottom surface for contacting the running surface, said padhaving side edges extending from the heel to the toe areas of the shoeupper portion; and a plurality of resilient cleats having a truncatedcone configuration fixed to the bottom surface of said cushioning padand projecting therefrom to contact the running surface, said cleatsadjacent the toe areas being tilted in a direction towards a side edgeof the pad to a line extending from the toe to heel areas of the shoeand said cleats in the heel area tilting in a direction towards or awayfrom the toe area of the shoe upper portion.
 3. An athletic shoe asdefined in claim 2 wherein half the cleats adjacent the heel and toeareas of the shoe tilt in opposite directions from the other half.